Kinda going on a whim here, but here are some examples of how I've seen it done:

• people worried their bi partner will cheat/break up with them if they "flip" -- this isn't even necessarily a thing, and even if it is, why attack that one aspect of our sexuality? People of all sexual orientations can experience sexual and/or romantic dissatisfaction at some point in their relationships.

• resentment towards bi people due to our ability to adapt and love people of a gender different from our dating history or even usual preference -- our behaviour is seen as deceptive, unethical, and/or choosing privilege over hardship (as if attraction and availability were a choice)

I see these notions embedded everywhere in concerns about dating bi people, and it's bringing us down :( Feel free to disagree with me or add to this, I'd live to hear your thoughts.